During routine dissection, of 70 year old donated embalmed male cadaver in the Department of Anatomy, at K.J. Somaiya Medical College, Sion, Mumbai, India, a hard bulge was observed in the distal part of descending colon. On incising, a mass was observed in its posterior wall. It measured 5cm x 5cm encircling nearly half the lumen but not showing any signs of obstruction. Histopathology confirmed the diagnosis of adenocarcinoma. Colorectal cancer (CRC) is the fourth most common malignant neoplasm in the world, and also the most frequent in the digestive tract, presenting with high mortality rates. Cancers on the right side of the large intestine (ascending colon and caecum) tend to be exophytic and rarely causes obstruction while left-sided tumors tend to be circumferential and can obstruct the bowel lumen. 90% cancers are adenocarcinomas which is a malignant epithelial tumor, originating from superficial glandular epithelial cells lining the colon and rectum. Likelihood of cure is greater when disease is detected at early stage. Early detection and screening is of pivotal importance. Colonoscopy detects some colon polyps and cancers early enough that they may be treated.